A Kremlin Offer of Expedited Citizenship Challenges Ukraine

President Vladimir V. Putin of Russia signed a decree on Wednesday simplifying the citizenship process for people in separatist-held regions of Ukraine, issuing a challenge to Ukraine’s president-elect that threatens to intensify the five-year war in the country’s east.

The decree, published on the Kremlin’s website, said that some residents in the regions of Donetsk and Luhansk, eastern parts of Ukraine controlled by Russia-backed rebels, could have their applications for Russian citizenship considered for acceptance within three months.

The order to simplify the citizenship process was made for the “humanitarian goals” of defending the “rights and freedoms of a person and citizen, outlined by the universally accepted principles and norms of international law,” its text said.

Yet the decree was immediately perceived as a challenge in Washington and Kiev, the Ukrainian capital, where the outgoing president has tried to rally the country on a platform of war and nationalism and the incoming president will take office with no political experience.

The current president, Petro O. Poroshenko, wrote on Twitter that Russia’s action was “another unprecedented intervention by the Russian Federation into the internal affairs of a sovereign state.” He urged other nations to condemn the decree and increase sanctions on Russia, and said that the Kremlin’s actions could “torpedo the peace process” to end the war.

Peace talks have faltered, but some hope for them had returned this year with the election of Volodymyr Zelensky, an actor whom Mr. Poroshenko criticized as being too inexperienced to confront Mr. Putin.

In a statement, Mr. Zelensky’s office said that the decree did “not bring us closer to the main goal of stopping the war” and called Russia the “aggressor state,” according to The Associated Press.

The United States, which has led efforts to punish Russian actions with sanctions, also denounced the Russian decree, saying it created “a serious obstacle” to peace efforts in eastern Ukraine.

“Russia, through this highly provocative action, is intensifying its assault on Ukraine’s sovereignty and territorial integrity,” Morgan Ortagus, a spokeswoman for the State Department, said in a statement. She added that Mr. Zelensky had expressed his willingness to hold peace talks with the Kremlin, saying, “It is now up to Russia to decide whether it wants to continue to escalate tensions.”